Problem: If you flip three fair coins, what is the probability that you'll get all three tails?
Answer: $\text{Probability} = \dfrac{\text{Favorable outcomes}}{\text{Total possible outcomes}}$ If we flip three coins, there are $2$ possible outcomes for each individual flip, so there are $2\times2\times2=8$ total possible outcomes. Each outcome is equally likely. The green row shows the outcome with three tails. There is $1$ favorable outcome. First Second Third H H H H H T H T H H T T T H H T H T T T H ${\text{T}}$ ${\text{T}}$ ${\text{T}}$ The probability of getting three tails is $1$ out of $8$, or $\dfrac18$.